I have a 1979 300D. I am having problems with the car holding power on a hill. I have read your diesel forum for days. Primer Pump is leaking, have purchased a new one, the little black one that is different from the old one. Diesel injection hose is leaking, have purchased all new. Have purchased new remanufactured injectors from Carquest(Bosch). We will be doing all of this on maybe tomorrow. I am a female but have a mechanical minded man willing to do this but I will assist. I have read a lot about algae/water in tank and feel that I need to approach this problem along with the others. I run Redline through most tanks of fuel but I don't think that this handles algae. I have a bottle of Power Service Diesel Supplement Cetane Boost, is this better than Redline? I live in Burlington NC and need to find something for possible algae problem quick. The clear fuel filter is dark in a lot of areas, I do have both filters new to replace. Have had all linkage aligned by independant MB mechanic but he's saying he needs to go into fuel pump at a pretty penny. Any input will be greatly appreciated!

Do everything you are doing. Going to the IP with your mech is a bad idea, as more than likely he doesn't know what he is doing anyway and they are very tech and expensive. You can buy another used one that is good for way cheaper if that is your problem. But I bet it isn't. You have plenty of other problems identified that would likely be the culprit.

As for algea just run a search as there are a couple of different brands out there, and it doesn't take much, just a cap full or so.

__________________
76 300D 130K "Stella" (Sold )
74 240D 299K (Donated to Highschool For Senior Project WVO)
83 300TDT 290K (My one and only)
Sanford, NC

The first thing is to replace that leaking primer pump -- that will likely cure most of the problem. Second is all the associated fuel line, especially the one between the steel supply line and the lift pump (where the hand pump is). It's likely porous, and leaks air in. This results in poor fuel delivery, worst at full throttle.

Do not mess with the IP unless you cannot fix it any other way -- they are quite robust and almost never fail, and do not cause lack of power with no other symptoms.

I would then make sure the line from the intake manifold at the rear (white plastic) to the switchover valve on the firewall and then to the ALDA (altitude adjuster) on the injection pump is clear and holds pressure. As the intake manifold pressure rises from turbo boost, the ALDA will cause increased fuel delivery. If that plastic line is plugged, broken, of the switchover valve is bad, you won't get the added fuel and it will run like an NA diesel (less power). If you don't have a turbo, this does not apply...

If the above things don't cure the problem, report back...

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thanks Guys...Have enjoyed your forum. Great info. Have learned a lot. Will head to Wal- Mart for something to clean up fuel! I just love this car and hope to have her for years to come! Had another engine dropped in 8 months ago. Starts great with good compression! The old engine probably had near a half million miles...I am sold!

Peter... as far as I know this is not a turbo,but a straight 300D 1979. Have double checked this with ASAP motors in Houston where engine came from. There was not a turbo on it. The engine is a 617.912. The # on the engine is 617 011 03 01 with a # under it 044 73, I got this # off of the driver's side of the engine block myself.

Hello tc art
You have a
300D (non-Turbo, OM 617.912 "65" kw/88 PS) engine.

"psfred" is correct; you must first replace the leaking primer pump to cure most of the issues, and replace all rubber fuel lines, they are likely porous, and leaking air in, this results in poor fuel delivery, worst at full throttle.
Do not mess with the IP unless you cannot fix it any other way -- they are quite robust and almost never fail, and do not cause lack of power with no other symptoms.
If the above things don't cure the problem, report back...

Algae will not be killed by Power Service Diesel Supplement Cetane Boost or
Redline.


Sounds like you are suffering fuel system air leak and possible Algae contamination.
Please read these threads to clean up the fuel system.

MB diesel filtration, how it works.
http://www.peachparts.com/shopforum/diesel-discussion/141211-mb-diesel-filtration-how-works.html#post1055075

fuel filter change
http://www.peachparts.com/shopforum/diesel-discussion/112664-fuel-filter-change-post824006.html

Diesel filters, no tank strainers please.
http://www.peachparts.com/shopforum/diesel-discussion/140349-diesel-filters-no-tank-strainers-please-post1046422.html?posted=1

I'm baffled and at wit's end!?!?!?!?!
I'm baffled and at wit's end!?!?!?!?!

Algae/Fungus fixation...
Algae/Fungus fixation...

Braided fuel lines weep. 1984 300TD turbo
Braided fuel lines weep. 1984 300TD turbo

240D fuel tank removal and cleaning
Good for any W123 sedan.
http://www.peachparts.com/shopforum/diesel-discussion/92826-240d-fuel-tank-removal-cleaning-post813925.html

Check out this fuel pickup screen
Check out this fuel pickup screen

300SD Fuel Filter Replacement Instructions
300SD Fuel Filter Replacement Instructions

Biobor, what is it, why do I need it???
http://www.peachparts.com/shopforum/diesel-discussion/105304-biobor-what-why-do-i-need.html#post723857

Filters, Fungus, Biocide, etc.
http://www.peachparts.com/shopforum/diesel-discussion/115952-filters-fungus-biocide-etc-post823378.html

Algae Clogged Filter Pic StarTron WORKS !
Algae Clogged Filter Pic StarTron WORKS !

Biodiesel and WVO - SVO links thread.
Biodiesel and WVO - SVO links thread.

I just bought Diesel Kleen by Power Service, Marvel Mystery Oil and STA-BIL Fuel Stabilizer. I did read about Biocore on your forum and will order some if that is what is necessary to cure all fuel evils. Will any of the above mentioned clean it up...Thanks T.C.

The product name is Biobor, and it does not cure all possible fuel issues, only Algae growth.
Most boating stores carry it..

Mr. Hunter...Thanks for engine info.! I think that I have been getting the run around from mechanic! Will proceed with all of above mentioned and post results. I may have just gotten bad fuel at a Citgo place in Raleigh...I usually try to fill up with BP...Thanks...T.C.

If you have not already done so, change out the clear plastic fuel pre-filter and then watch it closely... for if it shows the same black contamination again soon, then you are probably in need of a flush of the fuel tank to get rid of the dead algae.

A good way to thoroughly examin the clear plastic fuel pre-filter is to shine a bright light through from below so you can see the internal condition clearly.

P.S. - Complete your signature so your car's basic YR/MODEL etc are always present for us [see below]. Your location would also help us to judge if it's warm enough to be an extra algae problem climate.

Regards,

Thanks... My location is Burlington NC. Will check pre-filter every day. Thanks for input!

Regards,
T.C.
1979 300D(non-turbo) Silver

Hi...Fuel injectors replaced, Injection hoses replaced, Primer pump replaced, no leaks in any of above mentioned. Pre-Filter replaced, there was black stuff in the old filter but so far filter is clean and have been running it up and down the road. The spin on filter is leaking a lot at the bolt that holds the cannister on. Where do I get the aluminum ring seal for this? This filter was a little smaller than the old one , it came from
Carquest but everything lined up the same. Any suggestions? Does anyone know a good mechanic for this car in Burlington, NC?

Thanks again,
T.C.
1979 300D non-turbo silver
Burlington, NC

ShopForum > General Discussion > Good MB Shops
North Carolina

http://www.peachparts.com/shopforum/north-carolina/

Spin-On Fuel Filter- I checked with my favorite WebSite source at:
http://www.performanceproducts4benz.com/Drawings.aspx?bmid=151 You will have to "click" and "right-click" to learn how to zoom in/out on this WebPage's graphics... and when you have zoomed in, you will find that parts #101 and #102 in the graphic are rubber and metal respectively and are described in the space below the graphic as being "fuel filter seal rings".

Replacing these and then tugging/torqueing the hollow bolt down should solve your filter leak.
Regards,

Mr. Hunter...Thanks for info. Mr Ross...Thanks for info. on web-page. Ordered a Fuel Filter seal ring, fuel return hose, new spin on filter and a bulk fuel hose. Reasonable prices, had not found this web- page before. Have found improvement with performance on hill but still lagging at the top of long hill. Marked improvement on shorter hills. Will replace filter and seal ring and other hoses and go from there! This old Mercedes is the best riding car in the world so I will certainly solve this issue!

Thanks so much
T.C.
1979 300D non-turbo Silver